This invention relates to improvements in container closures, and more particularly to a reusable cap for mounting on a seal closure or stopper inserted into the neck of a vial to retain the seal.
Reusable plastic containers or caps for retaining the seal of stoppers inserted into the neck of a vial have been developed particularly for reuse in contact lens fitting procedures. Large numbers of vials containing test or examination lenses must be repeatedly subjected to a high-temperature sterilization and disinfection cycle following each use of the contained examination lens employed in testing multiple patients. As a result, the retaining cap must be repeatedly mounted and dismounted on the stopper and vial neck, as well as subjected to heating and cooling in the sterilization operation. For example, U.S. Pat. No. 4,480,762 describes a reusable plastic cap for retaining the sealed closure on vial necks in which a molded cap of resilient material has a base overlying the seal closure or stopper inserted in the vial neck and has opposed jaws on the base for gripping bead on the vial neck; the base also includes a pair of gripper flanges for manual engagement to spread apart the jaws during the mounting or removal of the cap on the vial neck, and a locking bar which assists in retaining the jaws in locked position on the vial neck by holding the gripper flanges spread apart. In general the cap described in this patent was designed for use with a vial neck and stopper head of specific dimensions in order to ensure the sealed condition during the high-temperature disinfection operation.
The cap in accordance with the subject invention provides for accommodation of vial necks and stoppers having a variation in dimensions, and assures proper sealing without over stressing the cap and reducing its useful life particularly under cycled heating and cooling conditions.